The present invention is intended for use in infrared image viewing systems.
A typical infrared (IR) imager consists of an IR radiation image gathering device such as an IR telescope, an optical-mechanical scanner mirror, an IR collimator lens, and a detector means with processing electronics and a display means. The IR radiation, impinging on the IR telescope, is transmitted to the optical-mechanical scanner whereby the IR radiation is reflected off the facets of a multifaceted scanner and through the IR collimator and is focused on the detector means. The output signals from the detector means are amplified, processed, and displayed to an operator.
The exit pupil of the IR telescope is normally positioned at approximately the scanner mirror facet surface. As the scanner mirror rotates, the scanner mirror facets move with respect to the incoming bundle of radiation rays from the telescopic lens. Each facet must be large enough (or equivalently, the bundle of radiation small enough) so that no radiation misses the facet in any part of the field-of-view of the detectors.